The present invention relates generally to a removable electronic device and, more particularly, to a removable memory card standard and method thereof.
A memory card is commonly known as a small portable package containing digital memory, such as an array of non-volatile memories, such as flash memories, EPROMs, or EEPROMs (electrically erasable and programmable read only memory). Memory cards have gain popularity as a device for storing a substantial amount of bytes of data from personal computers, notebook computers, personal electronic assistants, cellular telephones, cameras and other electronic devices that support removable data storage.
In general, a memory card includes exposed electrical contacts on its surface to allow easy connection to and removal from a receptacle of a host electronic system or device, particularly portable devices. A number of standards for a memory card have been implemented, including the MultiMedia Card (“MMC”) by the MultiMedia Card Association (“MMCA”) of Cupertino, Calif. An MMC is a compact, removable memory card for storing and retrieving digital information in small, low power devices. MMC has been used in many mobile electronic applications, such as music players, mobile phones, personal digital assistants (PDAs), digital cameras, voice recorders, and GPS navigation devices. The MMCA developed and regulated its open industry standards, and also defined all types of MMCs as an industry standard across multiple host platforms and markets. The physical and electrical specifications for the MMC are given in “The MultiMediaCard System Specification” that is updated and published from time-to-time by the MMCA.
Another known standard for a removable memory card, although not limited to memory storage, is the Universal Serial Bus (“USB”). USB is a high-speed serial bus that supports devices such as printers, keyboards, scanners, pointing devices, and PDAs. USB has become a standard within the computer industry as this protocol affords networking of multiple devices with minimal connections and increased user friendliness. USB is currently defined by the Universal Serial Bus Specification, written and controlled by USB Implementers Forum, Inc., a non-profit corporation founded by a group of companies that developed the USB specification. The specification covers all aspects of USB operations, including electrical, mechanical, and communications characteristics and specifications. One significant feature of the USB is that it allows a peripheral device to store information about itself, and to provide such information upon request by the host. This obviates the need for the host, be it a computer, operating system, or application program, to maintain this information for many different devices. Instead, the device itself stores and provides the information.
In the evolution of memory cards, it is desirable to have memory cards that consumes low power and provides higher speed for accessing, while still retaining backward compatibility with existing protocols such as the MMC and USB specifications.